Question

Select the activated form of oncogenes.

• A. Proto oncogenes
• B. House keeping genes
• C. Tumor Suppressor genes
• D. Repair genes

Hint:

Proto-oncogene: \[ \text{Normal gene} \] Oncogene: \[ \text{Mutated cancer-causing activated gene} \]

Answer 1

The Correct Option is A

Concept: Oncogenes are genes that have the ability to transform a normal cell into a cancerous cell. Normally, cells contain: \[ \boxed{ \text{Proto-oncogenes} } \] These are normal genes involved in:
• Cell growth
• Cell division
• Cell differentiation When proto-oncogenes undergo mutation or abnormal activation, they become: \[ \boxed{ \text{Oncogenes} } \]

Step 1: Understand proto-oncogenes. Proto-oncogenes are:
• Normal cellular genes
• Important for regulated cell growth Under normal conditions:
• Cell division remains controlled.

Step 2: Understand formation of oncogenes. When mutations occur due to:
• Radiation
• Chemicals
• Viruses proto-oncogenes become permanently activated. This activated form is called: \[ \boxed{ \text{Oncogene} } \] These oncogenes:
• Cause uncontrolled cell division
• Lead to cancer formation

Step 3: Analyze all options carefully.
• Proto-oncogenes are the precursor normal genes that become activated oncogenic forms.
• Housekeeping genes maintain basic cellular functions.
• Tumor suppressor genes prevent cancer.
• Repair genes help repair damaged DNA. Thus the correct related answer is: \[ \boxed{ \text{Proto-oncogenes} } \]

Step 4: Choose the correct answer. Hence correct option is: \[ \boxed{(1)} \] Final Conclusion: Activated cancer-causing genes originate from: \[ \boxed{ \text{Proto-oncogenes} } \] Hence correct answer is: \[ \boxed{(1)} \]